Final answer:
John Rawls's thought experiment is known as the Veil of Ignorance, which is designed to help individuals create principles for a just society without knowing their place in it, promoting equity and fairness.
Step-by-step explanation:
The thought experiment used by John Rawls is called the Veil of Ignorance. This experiment is central to Rawls's theory of justice, which posits that people should decide the principles of a just society without knowing their own future position within that society. By doing so, Rawls argues, individuals would create a more equitable system that ensures fairness and justice since they would not want to disadvantage any particular group, including potentially themselves. This exercise helps to eliminate biases and develop a society that addresses inherent structural inequalities. Rawls introduces two principles: the liberty principle, which advocates for equal basic liberties for all, and the difference principle, which allows for social and economic inequalities only if they benefit the least advantaged members of society and conform to fair equality of opportunity.